Roof tiles question

[UndercoverElephant]

OK...so our surveyor tells us the roof tiles all need replacing within 5 years, and that the existing tiles contain asbestos. His ballpark estimate for replacement was heading towards £20K - although that includes the cost of scaffolding, which was an expense we already knew was coming, because we want to install a PV system. We are going to have to get this done if we go through with this purchase, because there's absolutely no point in installing a PV system with a 30 year life expectancy over tiles that will need to be replaced in the forseeable future. We want to get the solar panels installed within 18 months anyway, and it would be crazy not to replace the tiles at the same time. We haven't got that sort of money available in that time-frame, so this is going to require the vendor to accept some of the cost.

My question is this: what sort of tiles should we be planning to replace them with, at the same time as the PV system is installed?

Are https://www.ecosystemsdistribution.com/eco-slate/ any good?

Also, what other eco-functionality work should we schedule at the same time?

[kenneal - lagger]

I presume that the tiles are asbestos/cement mock slates and they can be replaced with fibre/cement mock slates of more or less the same size and weight. If you are putting up a large area of PV you could use one of the mounting systems which are weather proof and don't require any tiles underneath. This will save weight and cost as a roof with fibre/cement tiles might not be as strong as one designed for clay or concrete tiles.

That system looks interesting and I haven't seen it before. Because it's new it might be expensive and it might be expensive to have installed as I doubt that any contractors have seen it before.

The most common replacement for asbestos/ cement tiles would be this

https://www.roofingsuperstore.co.uk/bro ... lates.html

I would think about insulating the roof while you are reroofing with 100 mm or thereabouts of a PIR foam between the rafters and 200 fixed on top of the rafters.

[UndercoverElephant]

I presume that the tiles are asbestos/cement mock slates

Yes.

and they can be replaced with fibre/cement mock slates of more or less the same size and weight.

Is there any reason why they couldn't be?

If you are putting up a large area of PV you could use one of the mounting systems which are weather proof and don't require any tiles underneath. This will save weight and cost as a roof with fibre/cement tiles might not be as strong as one designed for clay or concrete tiles.

So the PV system effectively becomes the roof? I didn't know that was possible.

I would think about insulating the roof while you are reroofing with 100 mm or thereabouts of a PIR foam between the rafters and 200 fixed on top of the rafters.

Surveyor said there was already a lot of insulation up there.

[clv101]

Yeah, the integrated panels look really smart. Don't know how they stack up economically. Can't have too much insulation, we have 320mm wood fibre insulation between and on our rafters. Easy to fit large boards above rafters when tiling, relatively little extra labour cost.

[UndercoverElephant]

So next question. If we replace the tiles on the south-facing part of the roof with solar electric panels, but aren't ready to do the modifications to the rest of the house - which would include installing a thermal store - can we initially just hook the panels up to our electric system with a feed in tariff, and then reconnect them to a thermal store later on? Or would the panels need to be changed? Or is there some other problem with doing it this way?

[clv101]

Bog standard grid tied system works fine, when you come to fit the plumbing there's a gizmo that monitors the inflow-outflow of power and tries to minimise net outflow by diverting to immersion heater. Nothing needs to change with the PV system.

[UndercoverElephant]

Bog standard grid tied system works fine, when you come to fit the plumbing there's a gizmo that monitors the inflow-outflow of power and tries to minimise net outflow by diverting to immersion heater. Nothing needs to change with the PV system.

Great. That's what the plan is then.

[emordnilap]

A friend has one of these; she has 55ºC hot water 24 hours a day. The power is supplied by her solar PV, which also charges her car.

https://www.thermasol.ie/the-lmtb-3/

[kenneal - lagger]

You will probably want to add extra insulation to the thermal store as they are fitted with the "economic" level of insulation. The economics of when the store was designed are a lot different to the economics of now and will probably be a lot different to when you get round to the installation!! About a foot of extra scrap shredded polystyrene inside some left over boards of some sort will do and won't cost you much at all.